Time Management

Most Americans “lost” an hour Sunday when Daylight Saving Time (DST) came into being at 2 a.m. as per the popular reminder, “Spring Forward, Fall Back.” I lost another 20 minutes resetting household clocks, light timers, automobile clocks, watches and appliances. As one who conducts business in a 24/7 world, I wondered how the practice came into being and what its purported benefits are.

History
According to the Discovery.com site, more than 200 years ago, Benjamin Franklin suggested in writing that an adjustment in time might save on candles. In 1895, a New Zealand entomologist named George Vernon Hudson proposed the modern version to the Wellington Philosophical Society proposing a two-hour daylight-saving shift (mostly so he could catch insects after his workday was complete). Prominent English builder and avid golfer William Willett conceived DST in 1905. Not only was he dismayed at the number of English who slept late during the summer, but he hated having his golf game called because of dark.

The practice of adjusting the clock was first tried (for only a year) in 1918. This World War I effort was enacted in several countries to conserve fuel. It was thought that citizens could decrease the need for artificial light by changing summer hours to match the hours that people were awake. During World War II, the United States again took up the practice to conserve energy from 1942 to 1945.

In 1966, the U.S. officially adopted the Uniform Time Act of 1966, which decreed that Daylight Saving Time to begin on the last Sunday of April and end on the last Sunday in October. The Energy Policy Act of 2005 changed the dates so that DST begins at 2 a.m. on the second Sunday of March and ends at 2 a.m. on the first Sunday in November.

Compliance
Most of North America and Europe observes DST (or “summer time” as it’s termed in Britain). States in the U.S. are not required to comply with the Energy Policy Act of 2005. Arizona (excluding the Navajo Nation), Hawaii, Puerto Rico, Guam, American Samoa and the Virgin Islands remain on standard time. Most of these indicate the extraordinary heat and sunlight they have already results in the lack of need for additional hours of daylight.

There are incidents of start-and-stop implementation, of neighboring cities on different times (especially during the 1950s and 1960s), and of complications in adjusting time. But North American, for the most part, has settled into this pattern.

Effectiveness
A U.S. Department of Transportation study in the 1970s found that daylight saving reduced electricity usage by about 1 percent. However there are other studies in place that suggest any savings incurred is lost because air conditioners continue running in warmer climates. In 2007, a survey by RAND Corporation reported that the increase in daylight in spring was corollary to a 10 percent drop in vehicular crashes.

An article in Scientific American exploring the efficacy of DST suggests disadvantages (farmers have long expressed concern on how it upsets their schedules) as well as benefits:

Retailers, especially those involved with sports and recreation, have historically argued hardest for extending daylight time. Representatives of the golf industry, for instance, told Congress in 1986 that an extra month of daylight saving was worth up to $400 million annually in extra sales and fees.

A Viable Explanation
The graphic below was designed by a Visual.ly member under the name Germanium, and graphically explains the result of recognizing Daylight Savings Time. He explains:

I wanted to see the effect of daylight saving time change on sunrise and sunset times. The data was taken from http://www.timeanddate.com and is for Chicago. The figure shows that daylight saving time change (marked by the DLS lines) keeps the sunrise time pretty much constant throughout the whole year, while making the sunset time change a lot. The spread of sunrise times for the whole year as measured by the standard deviation is 42 minutes, while for sunset times is 1:30 hours.

The graphic represents sunrise and sunset times throughout the year. In visualizing the daylights hours, a pattern emerges that suggests DST is designed to keep the sunrise time constant.

Throughout its long and fascinating history, daylight saving time has had a remarkable impact on a wide variety of unexpected areas–from Middle East terrorism to feuding twin cities, voter turnout to time-change riots, radio stations to trick-or-treaters, and opera performances to manslaughter charges.